That depends on your definition of the word “atheist.” The American Heritage Dictionary defines “atheism” as “Disbelief in or denial of the existence of God or gods.” Under this definition, which does not specify that gods are “all-powerful” or that gods created the universe, Epicurus was not an atheist. Epicurus held there to be a race of perfect, immortal gods living in distant parts of the universe who neither created the universe, control it, or have any concern for the happenings on Earth.

From the opening of Epicurus’ Letter to Menoeceus: “First believe that God is a living being immortal and blessed, according to the notion of a god indicated by the common sense of mankind; and so believing, you shall not affirm of him anything that is foreign to his immortality or that is repugnant to his blessedness. Believe about him whatever may uphold both his blessedness and his immortality. For there are gods, and the knowledge of them is manifest; but they are not such as the multitude believe, seeing that men do not steadfastly maintain the notions they form respecting them. Not the man who denies the gods worshiped by the multitude, but he who affirms of the gods what the multitude believes about them is truly impious. For the utterances of the multitude about the gods are not true preconceptions but false assumptions; hence it is that the greatest evils happen to the wicked and the greatest blessings happen to the good from the hand of the gods, seeing that they are always favorable to their own good qualities and take pleasure in men like themselves, but reject as alien whatever is not of their kind.”

The answer is different if your definition of “atheist” requires that gods be all-powerful or responsible for creation and direction of the universe – in other words that god is a “supreme being.” For example, Dictionary.com defines “atheist” as: “a person who denies or disbelieves the existence of a supreme being or beings.” By this definition, Epicurus does qualify as an atheist, as all Epicurean texts refer to gods as “a part” of Nature, and not as “supreme above” or “superior to” or “creator of” Nature itself.

What did Epicurus say about the origin of the universe?

Epicurus held that the elements from which the universe is composed are eternal. Although the atoms are constantly in motion and changing positions, such that the things we see now are not permanent, the elements themselves were never created at any point in time by any god or by any other means:

Letter to Herodotus: “To begin with, nothing comes into being out of what is non-existent. For in that case anything would have arisen out of anything, standing as it would in no need of its proper germs. And if that which disappears had been destroyed and become non-existent, everything would have perished, that into which the things were dissolved being non-existent. Moreover, the sum total of things was always such as it is now, and such it will ever remain. For there is nothing into which it can change. For outside the sum of things there is nothing which could enter into it and bring about the change.”

What did Epicurus have to say about how human (or animal) consciousness arose?

In regard to a question of physics such as this, in which our information is incomplete, we must keep in mind Principal Doctrine 24: “If you reject absolutely any single sensation without stopping to distinguish between opinion about things awaiting confirmation and that which is already confirmed to be present, whether in sensation or in feelings or in any application of intellect to the presentations, you will confuse the rest of your sensations by your groundless opinion and so you will reject every standard of truth. If in your ideas based upon opinion you hastily affirm as true all that awaits confirmation as well as that which does not, you will not avoid error, as you will be maintaining the entire basis for doubt in every judgment between correct and incorrect opinion.” In other words, where we have insufficient information to reach a conclusion, we consider as possible any theory which has evidence to support it, while rejecting any that have no evidence or which contradict known evidence. Further, as explained in the Letter to Pythocles: “For in the study of nature we must not conform to empty assumptions and arbitrary laws, but follow the promptings of the facts; for our life has no need of unreason and false opinion; our one need is untroubled existence. All things go on uninterruptedly, if all be explained by the method of plurality of causes in conformity with the facts, so soon as we duly understand what may be plausibly alleged respecting them. But when we pick and choose among them, rejecting one equally consistent with the phenomena, we clearly fall away from the study of nature altogether and tumble into myth. Some phenomena within our experience afford evidence by which we may interpret what goes on in the heavens. We see how the former really take place, but not how the celestial phenomena take place, for their occurrence may possibly be due to a variety of causes. However, we must observe each fact as presented, and further separate from it all the facts presented along with it, the occurrence of which from various causes is not contradicted by facts within our experience.”

In his letter to Herodotus, Epicurus wrote that the “soul” is composed of a particularly fine type of atoms of a unique type which themselves have no sensation apart from the body, but which carry the potentiality of sentience in combination with the body. Neither these particles, nor any other particles, can combine except according to the laws of Nature: “Next, keeping in view our perceptions and feelings (for so shall we have the surest grounds for belief), we must recognize generally that the soul is a corporeal thing, composed of fine particles, dispersed all over the frame, most nearly resembling wind with an admixture of heat, in some respects like wind, in others like heat. But, again, there is the third part which exceeds the other two in the fineness of its particles and thereby keeps in closer touch with the rest of the frame. And this is shown by the mental faculties and feelings, by the ease with which the mind moves, and by thoughts, and by all those things the loss of which causes death. Further, we must keep in mind that soul has the greatest share in causing sensation. Still, it would not have had sensation, had it not been somehow confined within the rest of the frame. But the rest of the frame, though it provides this indispensable conditions for the soul, itself also has a share, derived from the soul, of the said quality; and yet does not possess all the qualities of soul. Hence on the departure of the soul it loses sentience. For it had not this power in itself; but something else, congenital with the body, supplied it to body: which other thing, through the potentiality actualized in it by means of motion, at once acquired for itself a quality of sentience, and, in virtue of the neighborhood and interconnection between them, imparted it (as I said) to the body also. Hence, so long as the soul is in the body, it never loses sentience through the removal of some other part. The containing sheaths may be dislocated in whole or in part, and portions of the soul may thereby be lost; yet in spite of this the soul, if it manage to survive, will have sentience. But the rest of the frame, whether the whole of it survives or only a part, no longer has sensation, when once those atoms have departed, which, however few in number, are required to constitute the nature of soul. Moreover, when the whole frame is broken up, the soul is scattered and has no longer the same powers as before, nor the same notions; hence it does not possess sentience either. For we cannot think of it as sentient, except it be in this composite whole and moving with these movements; nor can we so think of it when the sheaths which enclose and surround it are not the same as those in which the soul is now located and in which it performs these movements. There is the further point to be considered, what the incorporeal can be, if, I mean, according to current usage the term is applied to what can be conceived as self-existent. But it is impossible to conceive anything that is incorporeal as self-existent except empty space. And empty space cannot itself either act or be acted upon, but simply allows body to move through it. Hence those who call soul incorporeal speak foolishly. For if it were so, it could neither act nor be acted upon. But, as it is, both these properties, you see, plainly belong to soul. If, then, we bring all these arguments concerning soul to the criterion of our feelings and perceptions, and if we keep in mind the proposition stated at the outset, we shall see that the subject has been adequately comprehended in outline: which will enable us to determine the details with accuracy and confidence.

We have a further explanation of these matters in Lucretius. In Book III, Lucretius wrote (translation by HAJ Munro):“Therefore, again and again I say, you are to know that the nature of the mind and the soul has been formed of exceedingly minute seeds, since at its departure it takes away none of the weight. We are not however to suppose that this nature is single. For a certain subtle spirit mixed with heat quits men at death, and then the heat draws air along with it; there being no heat which has not air too mixed with it: for since its nature is rare, many first beginnings of air must move about through it. Thus the nature of the mind is proved to be threefold; and yet these things all together are not sufficient to produce sense; since the fact of the case does not admit that any of these can produce sense-giving motions and the thoughts which a man turns over in mind. Thus some fourth nature too must be added to these: it is altogether without name; than it nothing exists more nimble or more fine, or of smaller or smoother elements: it first transmits the sense-giving motions through the frame; for it is first stirred, made up as it is of small particles; next the heat and the unseen force of the spirit receive the motions, then the air; then all things are set in action, the blood is stirred, every part of the flesh is filled with sensation; last of all the feeling is transmitted to the bones and marrow, whether it be one of pleasure or an opposite excitement. No pain however can lightly pierce thus far nor any sharp malady make its way in, without all things being so thoroughly disordered that no room is left for life and the parts of the soul fly abroad through all the pores of the body. But commonly a stop is put to these motions on the surface as it were of the body: for this reason we are able to retain life. Now though I would fain explain in what way these are mixed up together, by what means united, when they exert their powers, the poverty of my native speech deters me sorely against my will: yet will I touch upon them and in summary fashion to the best of my ability: the first-beginnings by their mutual motions are interlaced in such a way that, none of them can be separated by itself, nor can the function of any go on divided from the rest by any interval; but they are so to say the several powers of one body.

In Book II Lucretius had previously written: “Wherefore the bodies of the first-beginnings in time gone by moved in the same way in which now they move, and will ever hereafter be borne along in like manner, and the things which have been wont to be begotten will be begotten after the same law and will be and will grow and will wax in strength so far as is given to each by the decrees of nature. And yet we are not to suppose that all things can be joined together in all ways; for then you would see prodigies produced on all hands, forms springing up half man half beast and sometimes tall boughs sprouting from the living body, and many limbs of land-creatures joined with those of sea-animals, nature too throughout the all-bearing lands feeding chimeras which breathed flames from noisome mouth. It is plain however that nothing of the sort is done, since we see that all things produced from fixed seeds and a fixed mother can in growing preserve the marks of their kind. This you are to know must take place after a fixed law.….To come to another point, whatever things we perceive to have sense, you must yet admit all composed of senseless first-beginnings: manifest tokens which are open to all to apprehend, so far from refuting or contradicting this, do rather themselves take us by the hand and constrain us to believe that, as I say, living things are begotten from senseless things.…Therefore nature changes all foods into living bodies and engenders out of them all the senses of living creatures, much in the same way as she dissolves dry woods into flames and converts all things into fires. Now do you see that it is of great moment in what sort of arrangement the first-beginnings of things are severally placed and with what others they are mixed up, when they impart and receive motions? Then again what is that which strikes your mind, affects that mind and constrains it to give utterance to many different thoughts, to save you from believing that the sensible is begotten out of senseless things? Sure enough it is because stones and wood and earth however mixed together are yet unable to produce vital sense.”

What did Epicurus say was the "greatest good" of human life?

Norman DeWitt explains in Epicurus and His Philosophy that due to translation issues there is much confusion today between the concepts of the "greatest good" and the "goal" of human life. He explains the proper distinction in the chapter entitled "The New Hedonism" which contains the following:

"The belief that life itself is the greatest good conditions the whole ethical doctrine of Epicurus. He sees life as narrowly confined between the limits of birth and death. Soul and body are born together and perish together. Metrodorus gave telling expression in figurative language to this melancholy belief, Vatican Saying 30: "The potion mixed at birth for all of us is a draught of death." There was for Epicureans no pre-existence, as Plato believed, and no afterlife, as the majority of mankind believed. Epicurus himself expressed the thought with stark directness, Vatican Saying 14: "We are born once and we cannot be born twice but to all eternity must be no more." Thus the supreme values must be sought between the limits of birth and death. The specific teaching that life itself is the greatest good is to be drawn from Vatican Saying 42: "The same span of time includes both beginning and termination of the greatest good." If this seems to be a dark saying, the obscurity is dispelled by viewing it as merely a denial of belief in either pre-existence or the afterlife. As Horace wrote, concluding Epistle i.16 with stinging abruptness, "Death is the tape-line that ends the race of life." Editors, however, misled by the summum bonum fallacy, equate "the greatest good" with pleasure and so are forced to emend. The change of a single letter does the trick but fundamental teaching is obliterated. While this quoted statement is first-hand evidence of the Epicurean attitude, the syllogistic approach is also known from an extant text, of which the significance has been overlooked. The major premise is the assumption that the greatest good must be associated with the most powerful emotions, that is, the worst of all fears and the greatest of all joys. Now the worst of all fears is that of a violent death and the greatest of all joys is escape from the same. The supporting text runs as follows: "That which occasions unsurpassable joy is the bare escape from some dreadful calamity; and this is the nature of ‘good,’ if one apprehend it rightly and then stand by his finding, and not go on walking round and round and harping uselessly on the meaning of ‘good’." This passage marks the summary cutting of a Gordian knot, the meaning of "good," upon which Plato had harped so tediously. Epicurus finds a quick solution by appealing to the Feelings, that is to Nature, as the criterion; it is their verdict that the supreme good is life itself, because the strongest emotions are occasioned by the threat of losing it or the prospect of saving it.

Continuing in the same chapter ("The New Hedonism") DeWitt explains the distinction between the "greatest good," which Epicurus held to be life itself, and the "goal" of human life, which is pleasure:

"When once the summum bonum fallacy has been detected and the difference clearly discerned between the greatest good, which is life itself, and the end or telos, the next step is to apprehend clearly by what procedure the end or telos is identified as pleasure. The nature of this procedure and of the attitude which determined it was one thing in the time of Cicero and quite another in the time of Epicurus himself. In the space of the two centuries between these two men the study of formal logic had been forced into a dominating position in the curriculum through the aggressive genius of the Stoic Chrysippus, and after his time the incessant needling of Stoic adversaries had shaken the confidence of many Epicureans in the word of their founder. The faith of Epicurus himself had pinned itself upon Nature as the norm, not upon Reason. The faith of the Stoic, on the contrary, and of those Epicureans who wavered in their faith, while ostensibly pinned upon Reason, may more correctly be said to have been pinned upon argumentation and disputation. When Epicurus himself identified pleasure as "the end of Nature" he was setting Reason aside and recognizing Nature as the norm or as furnishing the norm. In this he was merely following a trend of his time. The brilliant Eudoxus, for example, who had preceded him by no great interval, also declared pleasure to be the good and he took his start from the observation that all creatures, whether rational or irrational, pursued it. Confirmation for the truth of this observation was found in the behavior of all creatures toward pain. If we may accept as authentic the tradition as reported by Aristotle, it would seem that Eudoxus thought of the pursuit of pleasure as comparable to the instinct of wild creatures to seek their proper food and to avoid the opposite. This demonstrates clearly the incipient tendency to recognize Nature as furnishing the norm. Thus the originality of Epicurus did not consist in recognizing Nature as furnishing the norm but in working out this principle to its utmost limit, which he did by setting up his Canon, each item of which, Sensations, Anticipations, and Feelings, was a separate appeal to the authority of Nature. In identifying pleasure as the end or telos it is both possible and probable that Epicurus was taking up a suggestion of Aristotle, who dropped the hint in this instance that the evidence drawn from the behavior of irrational creatures is superior in value to the evidence drawn from the behavior of rational creatures.6 At any rate the declaration of Epicurus, as reported by Cicero, runs as follows: "Every living creature, the moment it is born, reaches out for pleasure and rejoices in it as the highest good, shrinks from pain as the greatest evil, and, so far as it is able, averts it from itself." In the evaluation of this text the important words are "the moment it is born." By narrowing the field of observation to the newborn creature Epicurus was eliminating all differences between rational and irrational creatures. In infancy even the creatures that by courtesy we call rational are as yet irrational. By narrowing the field to the newborn Epicurus was also reducing animate life to its minimum value, because at the moment of birth even some of the senses have not yet begun to function. Consequently, as Cicero says in the same context, "since nothing is left of a human being when the senses are eliminated, the question, what is according to Nature or
contrary to Nature, is of necessity being judged by Nature herself." It is doubtful whether any other item of Epicurean invention is the equal of this in logical acumen. Even if weight be allowed to the later objection of the Stoics that the behavior of the infant has its cause in what we now call the instinct of self-preservation, this interpretation would lead to the recognition of life as the greatest good, which was the doctrine of Epicurus, and it would still be left for pleasure and pain to function as the criteria. Incidentally, this appeal to the evidence afforded by the newly born exercised its effect upon the terminology of Epicurus. The infant, being still in a state of nature, is "not yet perverted." These words afford a hint of the perversion ascribed to the study of rhetoric, dialectic, and mathematics, which a lad was judged lucky to have escaped. As for Nature herself, she speaks through the newly born "undefiled and uncontaminated." Her word is "true philosophy," the vera ratio so often invoked by Lucretius."

The major textual references advise Epicureans not to pursue politics, riches, fame, or other activities that are essentially competitive in nature, or require obedience or cooperation from other people. The common thread of this advice is that you cannot be happy if you are going to depend on other people to provide your happiness, so it is not wise to pursue happiness by seeking to "excel" over other people in any competitive endeavor.

But there is another sense of "excelling" that most people also associate with the word, and that is the important sense of not passively "accepting one’s lot in life," and working hard to succeed in taking advantage of those natural and proper pleasures that are within your power to achieve without violating some rule of nature. Phrases such as "accepting one’s lot in life" connotes idea that are fatalistic, religious, (and predominantly Stoic) and go against every central theme of Epicureanism, which is the pursuit of happiness through (1) the study of Nature and (2) action based on the results of that study.

For a few of the significant references to this issue, see the following:

PD 5. It is impossible to live a pleasant life without living wisely and honorably and justly, and it is impossible to live wisely and honorably and justly without living pleasantly. Whenever any one of these is lacking, when, for instance, the man is not able to live wisely, though he lives honorably and justly, it is impossible for him to live a pleasant life. <<<< One CANNOT live happily unless one diligently pursues wisdom, honor, and justice.

VS 5. We place a high value on our characters as if they were our own possessions whether or not we are virtuous and praised by other men. So, too, we must regard the characters of those around us if they are our friends. <<< It DOES matter what we think of ourselves, and what others think of us

PD 29. Of our desires some are natural and necessary, others are natural but not necessary; and others are neither natural nor necessary, but are due to groundless opinion. << And thus we diligently pursue those that are natural and necessary, and we judge and act wisely in pursuit of those that are only natural (but we do not ignore them).

VS 33. The cry of the flesh is not to be hungry, thirsty, or cold; for he who is free of these and is confident of remain so might vie even with Zeus for happiness. << And thus we pursue diligently the goal of avoiding hunger, thirst, and cold.

VS 36. Epicurus’s life when compared to that of other men with respect to gentleness and self-sufficiency might be thought a mere legend. << Epicurus EXCELLED in gentleness and self-sufficiency.

VS 41. At one and the same time we must philosophize, laugh, and manage our household and other business, while never ceasing to proclaim the words of true philosophy. << We do NOT ignore or deprecate the value of the management of our household business.

VS 45. The study of nature does not create men who are fond of boasting and chattering or who show off the culture that impresses the many, but rather men who are strong and self-sufficient, and who take pride in their own personal qualities not in those that depend on external circumstances. << This one is VERY clear. We are to excel in our strength, our self-sufficiency, and our personal qualities that do not depend upon others.

VS 58. We must free ourselves from the prison of public education and politics. << This is very close to the key issue, for it is freedom from these that we require in order to secure our own happiness.

And for a reference that me be the most direct of all on this point:

VS 63. There is also a limit in simple living, and he who fails to understand this falls into an error as great as that of the man who gives way to extravagance.

What did Epicurus say about "friendship"?

Key Doctrine 27: “Of all the things which the wise man seeks to acquire to produce the happiness of a complete life, by far the most important is the possession of friendship.”

Key Doctrine 28: “The same opinion that encourages us to trust that no evil will be everlasting, or even of long duration, shows us that in the space of life allotted to us the protection of friendship is the most sure and trustworthy.”

Key Doctrine 39: “He who desires to live tranquilly without having anything to fear from other men ought to make them his friends. Those whom he cannot make friends he should at least avoid rendering enemies, and if that is not in his power, he should avoid all dealings with them as much as possible, and keep away from them as far as it is in his interest to do so.

Key Doctrine 40: “The happiest men are those who have arrived at the point of having nothing to fear from their neighbors. Such men live with one another most pleasantly, having the firmest grounds of confidence in one another, enjoying the full advantages of friendship, and not lamenting the departure of their dead friends as though they were to be pitied.”

Vatican Saying 23. “All friendship is desirable in itself, though it starts from the need of help.”

Vatican Saying 28. “We must not approve either those who are always ready for friendship, or those who hang back, but for friendship’s sake we must run risks.”

Vatican Saying 34. “It is not so much our friends’ help that helps us as it is the confidence of their help.”

Vatican Saying 39. “He is no friend who is continually asking for help, nor he who never associates help with friendship. For the former barters kindly feeling for a practical return and the latter destroys the hope of good in the future.”

Vatican Saying 52. “Friendship dances around the world bidding us all to awaken to the recognition of happiness.”

Vatican Saying 56. “The wise man feels no more pain when being tortured himself than when his friend tortured.”

Vatican Saying 57. “On occasion a man will die for his friend, for if he betrays his friend, his whole life will be confounded by distrust and completely upset.”

Vatican Saying 61. “Most beautiful too is the sight of those near and dear to us, when our original kinship makes us of one mind; for such sight is great incitement to this end.”

Vatican Saying 66. “Let us show our feeling for our lost friends not by lamentation but by meditation.”

Vatican Saying 78. “The noble soul occupies itself with wisdom and friendship; of these the one is a mortal good, the other immortal.”

Wise Man Saying 5. “The wise man shows gratitude, and constantly speaks well of his friends whether they are present or absent.”

Wise Man Saying 24. “The wise man will not mourn the death of his friends.”

Wise Man Saying 37. “The wise man will be willing even to die for a friend.”

Wise Man Saying 41. “The wise man holds that friendship is first brought about due to practical need, just as we sow the earth for crops, but it is formed and maintained by means of a community of life among those who find mutual pleasure in it.”

Cicero’s “On Ends” – the Defense of Epicurus delivered by Torquatus: “There remains a topic that is supremely relevant to this discussion – the subject of Friendship. Your [Platonic] school maintains that if pleasure is held to be the Chief Good, friendship will cease to exist. In contrast, Epicurus has pronounced in regard to friendship that of all the means to happiness that wisdom has devised, none is greater, none is more fruitful, none is more delightful than friendship. Not only did Epicurus commend the importance of friendship through his words, but far more, through the example of his life and his conduct. How rare and great friendship is can be seen in the mythical stories of antiquity. Review the legends from the remotest of ages, and, many and varied as they are, you will barely find in them three pairs of friends, beginning with Theseus and ending with Orestes. Yet Epicurus in a single house (and a small one at that) maintained a whole company of friends, united by the closest sympathy and affection, and this still goes on today in the Epicurean school. … The Epicureans maintain that friendship can no more be separated from pleasure than can the virtues, which we have discussed already. A solitary, friendless life is necessarily beset by secret dangers and alarms. Hence reason itself advises the acquisition of friends. The possession of friends gives confidence and a firmly rooted hope of winning pleasure. And just as hatred, jealousy and contempt are hindrances to pleasure, so friendship is the most trustworthy preserver and also creator of pleasure for both our friends and for ourselves. Friendship affords us enjoyment in the present, and it inspires us with hope for the near and distant future. Thus it is not possible to secure uninterrupted gratification in life without friendship, nor to preserve friendship itself unless we love our friends as much as ourselves. … For we rejoice in our friends’ joy as much as in our own, and we are equally pained by their sorrows. Therefore the wise man will feel exactly the same towards his friends as he does towards himself, and he will exert himself as much for his friend’s pleasure as he would for his own. All that has been said about the essential connection of the virtues with pleasure must be repeated about friendship. Epicurus well said (and I give almost his exact words): “The same creed that has given us courage to overcome all fear of everlasting or long-enduring evil after death has discerned that friendship is our strongest safeguard in this present term of life. … All these considerations go to prove not only that the rationale of friendship is not impaired by the identification of the chief good with pleasure, but, in fact, without this, no foundation for friendship whatsoever can be found.

What did Epicurus say about the proper attitude to hold toward our past, present, and future?

Letter to Menoeceus: We must remember that the future is neither wholly ours nor wholly not ours, so that neither must we count upon it as quite certain to come nor despair of it as quite certain not to come.

Vatican Saying 10. Remember that you are mortal and have a limited time to live and have devoted yourself to discussions on nature for all time and eternity and have seen “things that are now and are to me come and have been.”

Vatican Saying 17. We should not view the young man as happy, but rather the old man whose life has been fortunate. The young man at the height of his powers is often befuddled by chance and driven from his course; but the old man has dropped anchor in old age as in a harbor, since he secures in sure and thankful memory goods for which he was once scarcely confident of.

Vatican Saying 19. He has become an old man on the day on which he forgot his past blessings.

Vatican Saying 35. Don’t spoil what you have by desiring what you don’t have; but remember that what you now have was once among the things only hoped for.

Vatican Saying 41. At one and the same time we must philosophize, laugh, and manage our household and other business, while never ceasing to proclaim the words of true philosophy.

Vatican Saying 47. I have anticipated you, Fortune, and entrenched myself against all your secret attacks. And we will not give ourselves up as captives to you or to any other circumstance; but when it is time for us to go, spitting contempt on life and on those who here vainly cling to it, we will leave life crying aloud in a glorious triumph-song that we have lived well.

Vatican Saying 48. While we are on the road, we must try to make what is before us better than what is past; when we come to the road’s end, we feel a smooth contentment.

Vatican Saying 55. We should find solace for misfortune in the happy memory of what has been and in the knowledge that what has been cannot be undone.

Vatican Saying 75. The saying, “look to the end of a long life,” shows small thanks for past good fortune.

What advice did Epicurus give about how much we should actively engage with society around us?

From the Principal Doctrines: 39. The man who best knows how to meet external threats makes into one family all the creatures he can; and those he can not, he at any rate does not treat as aliens; and where he finds even this impossible, he avoids all dealings, and, so far as is advantageous, excludes them from his life.40. Those who possess the power to defend themselves against threats by their neighbors, being thus in possession of the surest guarantee of security, live the most pleasant life with one another; and their enjoyment of the fullest intimacy is such that if one of them dies prematurely, the others do not lament his death as though it called for pity.

From Cicero’s De Finibus: “There remains a topic that is pre-eminently germane to this discussion, I mean the subject of Friendship. Your school maintains that if pleasure be the Chief Good, friendship will cease to exist. Now Epicurus’ pronouncement about friendship is that of all the means to happiness that wisdom has devised, none is greater, none more fruitful, none more delightful than this. Nor did he only commend this doctrine by his eloquence, but far more by the example of his life and conduct. How great a thing such friendship is, is shown by the mythical stories of antiquity. Review the legends from the remotest ages, and, copious and varied as they are, you will barely find in them three pairs of friends, beginning with Theseus and ending with Orestes. Yet Epicurus in a single house and that a small one maintained a whole company of friends, united by the closest sympathy and affection; and this still goes on in the Epicurean school.”

Vatican Saying 66. We show our feeling for our friends’ suffering, not with laments, but with thoughtful concern.

Vatican Saying 78. The noble man is chiefly concerned with wisdom and friendship; of these, the former is a mortal good, the latter an immortal one.

Given that Epicurus held that personal happiness is the goal of human life, to what extent did he hold that any and all paths to happiness are equally valid?

From Epicurus’ Letter to Menoeceus: When we say, then, that pleasure is the end and aim, we do not mean the pleasures of the prodigal or the pleasures of sensuality, as we are understood to do by some through ignorance, prejudice, or willful misrepresentation. By pleasure we mean the absence of pain in the body and of trouble in the soul. It is not an unbroken succession of drinking-bouts and of revelry, not sexual lust, not the enjoyment of the fish and other delicacies of a luxurious table, which produce a pleasant life; it is sober reasoning, searching out the grounds of every choice and avoidance, and banishing those beliefs through which the greatest tumults take possession of the soul. Of all this the beginning and the greatest good is wisdom. Therefore wisdom is a more precious thing even than philosophy ; from it spring all the other virtues, for it teaches that we cannot live pleasantly without living wisely, honorably, and justly; nor live wisely, honorably, and justly without living pleasantly. For the virtues have grown into one with a pleasant life, and a pleasant life is inseparable from them. “

Epicurus gave this description of the specific characteristics of the happiest possible man in the same Letter to Menoeceus: “Who, then, is superior in your judgment to such a man? He holds a holy belief concerning the gods, and is altogether free from the fear of death. He has diligently considered the end fixed by nature, and understands how easily the limit of good things can be reached and attained, and how either the duration or the intensity of evils is but slight. Fate, which some introduce as sovereign over all things, he scorns, affirming rather that some things happen of necessity, others by chance, others through our own agency. For he sees that necessity destroys responsibility and that chance is inconstant; whereas our own actions are autonomous, and it is to them that praise and blame naturally attach. It were better, indeed, to accept the legends of the gods than to bow beneath that yoke of destiny which the natural philosophers have imposed. The one holds out some faint hope that we may escape if we honor the gods, while the necessity of the naturalists is deaf to all entreaties. Nor does he hold chance to be a god, as the world in general does, for in the acts of a god there is no disorder; nor to be a cause, though an uncertain one, for he believes that no good or evil is dispensed by chance to men so as to make life blessed, though it supplies the starting-point of great good and great evil. He believes that the misfortune of the wise is better than the prosperity of the fool. It is better, in short, that what is well judged in action should not owe its successful issue to the aid of chance.

Vatican Saying 63. There is also a limit in simple living, and he who fails to understand this falls into an error as great as that of the man who gives way to extravagance.

To what extent does success in leading a happy life require an understanding of Nature?

Vatican Saying 49. (PD 12) It is impossible for someone to dispel his fears about the most important matters if he doesn’t know the nature of the universe but still gives some credence to myths. So without the study of nature there is no enjoyment of pure pleasure.

Vatican Saying 72. (PD 13) There is no advantage to obtaining protection from other men so long as we are alarmed by events above or below the earth or in general by whatever happens in the boundless universe.

What did
Epicurus say about the size of the sun and whether the Earth was round or
flat?

In the letter to Pythocles, Epicurus specifically makes clear before
he starts discussing astronomy that: "But this is not the case
with celestial phenomena: these at any rate admit of manifold causes for
their occurrence and manifold accounts, none of them contradictory of
sensation, of their nature. For in the study of nature we must not
conform to empty assumptions and arbitrary laws, but follow the
promptings of the facts; for our life has no need now of unreason and
false opinion; our one need is untroubled existence. All things go on
uninterruptedly, if all be explained by the method of plurality of
causes in conformity with the facts, so soon as we duly understand what
may be plausibly alleged respecting them. But when we pick and choose
among them, rejecting one equally consistent with the phenomena, we
clearly fall away from the study of nature altogether and tumble into
myth. Some phenomena within our experience afford evidence by which we
may interpret what goes on in the heavens. We see bow the former really
take place, but not how the celestial phenomena take place, for their
occurrence may possibly be due to a variety of causes. However, we must
observe each fact as presented, and further separate from it all the
facts presented along with it, the occurrence of which from various
causes is not contradicted by facts within our experience."
Then when he addresses the size of the sun, he says "The size of the
sun and the remaining stars relatively to us is just as great as it
appears. But in itself and actually it maybe a little larger or a little
smaller, or precisely as great as it is seen to be. For so too fires of
which we have experience are seen by sense when we see them at a
distance. And every objection brought against this part of the theory
will easily be met by anyone who attends to plain facts, as I show in my
work On Nature. "

Now his reason for this conclusion is clear from this — he says that
on earth, things that give off light do not appear to recede in the
distance as much as those things that don't. So applying that rule here,
there's no reason to think that the sun is a huge distance away, any
further than the moon, so no reason to think it is huge in size. Of
course a major reason he leaned toward this conclusion is that he was
battling the platonists, who said they were gods, and who were trying to
reduce nature down to a series of calculations. He chose incorrectly,
but he was motivated by good reasons. I believe much the same
explanation goes to the earth as well, which I gather they did think was
round, but that since everything falls down you would fall off the
bottom if you were on the other side. So there were good solid
reasons the Epicureans chose the positions they did, and definitely not
go along just because Epicurus said so.

The Place To Start:

If you are a new student of Epicurus, this is the book you want first: